Of the membranous insects with a poisonous stinger in Denmark, there are about 250 different kinds of bees, 20 different kinds of bumblebees, and between 4,000 and 5,000 different types of wasps, of which half a dozen hornets as well as ichneumon wasps and spider wasps have a poisonous stinger.
Each summer, these membranous insects cause much irritation and fear both in children and adults, who fear the stings of these insects. In Denmark, each year 10,000 patients are treated for insect stings, of which on average 2 patients die.
Membranous insects such as bees, wasps and hornets use their poisonous stinger as part of their defense. When the insect stings, poison is pumped out of the stinger and into the skin. The stings are always unpleasant and result after a few minutes to hours in swelling, flushing, pain, and skin irritation as well as itching that may last up to a week. Several stings, or a single sting in the case of an allergic person, can cause hazardous conditions such as anaphylactic shock with symptoms such as a swelling of the tongue, a drop in the blood pressure, respiratory distress, abdominal pain, nettle rash, vomiting and diarrhea. Bee poison contains a composition of acid fluids, which contain i.a. histamine and mellitine as well as enzymes that enhance the effect of the poison. The poison increases the blood flow to the sting wound and dissolves the red blood cells resulting in pain and a flushing of the sting wound. Bees are capable of attacking in swarms, which can pursue their victim and give the attacked person up to a dozen stings. The poison of the hornet is alkaline and contains more histamine than the poison of the bee, as well as serotonin, which is not contained in the poison of the bee. Due to the potency of the poison, it can be potentially lethal to small children of the age of 4 to 5 to get stung.
There are known methods for avoiding the unpleasant effects of insect stings such as to apply a local anesthesic onto the skin. This treatment only offers pain relief and does not remove the poison from the sting, which is desirable in order to reduce a potential allergic reaction.
Methods for removing the poison comprises different types of exhaust equipment such as e.g. the commercially available Giftsuger®. The end of such exhausters is placed over the sting to create a vacuum that absorbs the poison. The disadvantages of this method are that additional mechanical and painful stress is added to the already soar area, that only one sting can be treated at a time, and that the equipment as such can be inconvenient to bring in a bag or a pocket.
An old household remedy is to place a sugar cube on the stung area, by which the sugar will draw out the poison by means of osmosis. The disadvantages of this method is that the sugar cube quickly crumbles or partly dissolves and that the sugar cube is to be held on to the skin with a certain pressure which limits the method to only relieve one or two stings at a time. In addition to this, it is not desirable to a stung person to be in contact with sugar as such, since the insects are attracted to the sugar, which implies the risk of additional stings.
It has not been described previously to use patches for the extraction or expulsion of insect poison. However, patches that can exert pressure or that contain a local anesthetic have been used for open wounds and bites.
U.S. Pat. No. 5,823,983 relates to a patch with a swell layer, where blood or another liquid will make the layer swell and thus exert pressure on the wound at the same time as aspirating the blood. The patch is not suitable for bee stings, as it does not contain an agent, which can draw out poison.
WO03034900 relates to a patch containing anesthetics designed for open wounds. The patch is not suitable for bee stings, as it does not contain an agent, which can draw out poison and as the pressure required is not achieved.
WO0009176 relates to a patch, which can aspirate liquid from a wound by means of adsorption based on carbohydrates with the aim of reducing the healing period. Besides, the patch contains antibiotics and antiseptics and is thus primarily suitable for open wounds.
U.S. Pat. No. 6,120,792 relates to a patch with anesthetics and a liquid-aspirating layer. The patch is not suitable for insect stings, as it does not contain an agent, which can expel insect poison.